JP5519338B2 - Mixed powder for powder metallurgy and method for producing sintered body using the same - Google Patents

Description

  The present invention relates to a powder metallurgy technique for producing a sintered body by forming and sintering an iron-based powder, and preferably relates to a powder metallurgy technique that exhibits high flowability during transfer and high lubricity during compaction molding.

  In powder metallurgy for producing sintered bodies using iron-based powders such as iron powder and steel powder as main raw materials, the main raw material powder and the physical properties (strength characteristics and processing characteristics) of the sintered bodies are improved. It is common to use a mixed powder containing an auxiliary raw material powder (alloy component, graphite powder, etc.) and a lubricant. The mixed powder is filled in a mold, compression molded at a high pressure to form a green compact, and then the green compact is sintered to obtain a sintered body (product). In such a powder metallurgy method, in order to mass-produce a sintered body, the mixed powder is usually stored in a storage hopper in advance. And after discharging | emitting a predetermined amount of mixed powder from a hopper, it fills to a metal mold | die and performs until compression molding is performed continuously. In the mixed powder used in this way, its flowability is one of the important characteristics. If the flowability of the mixed powder is poor, problems such as bridging at the upper part of the discharge port of the hopper and causing discharge failure, or clogging in the transfer hose from the hopper to the shoe box (powder filling jig) occur. Moreover, even if the mixed powder having poor flowability is forced to flow out of the hose, the filling amount of the powder into the mold varies. In addition, the mold cavity (particularly the thin-walled portion) is not properly filled with powder, and a sound molded body may not be produced. Therefore, there is a strong demand for mixed powders with excellent flowability.

  The flowability of this mixed powder depends on the particle size and shape of the iron-based powder used, the type and amount of alloying powder and property improving agent, the particle size, and the shape, but it has the strongest effect. Is considered to be the type and amount of lubricant added. Since the flowability of the lubricant usually becomes worse as the addition amount reaches a peak of 0.1% by mass, the addition amount of the lubricant is preferably lowered from the viewpoint of flowability. However, if the addition amount of the lubricant is lowered, the lubricity is remarkably lowered, and the coefficient of friction between the molded body and the mold surface is increased when the molded body is extracted, which causes damage to the mold and the mold. Therefore, it has been difficult to achieve both lubricity and flowability.

  Further, it is difficult to achieve both flowability and lubricity from the viewpoint of the type of lubricant and the melting point. Further, if the lubricity is increased, defects in the molded body and sintered body are likely to occur. The lubricant exists in a dispersed state at the beginning of the production of the mixed powder. However, when the lubricant particles approach (contact) with each other during the subsequent handling up to molding, the particles may be aggregated and the particles may grow more than the original. When the agglomerated lubricant is present on the surface, it causes surface contamination of the molded body and surface roughness of the sintered body, and when it exists inside, it causes internal defects of the sintered body. In general, pulverized powders such as stearic acid and stearamide having a low melting point are excellent in lubricity, but tend to aggregate. For this reason, the flowability of the powder is deteriorated, and the surface of the molded body becomes dirty, the surface of the sintered body becomes rough, or internal defects are caused. In particular, the problem appears prominently when the environmental temperature is high. On the other hand, metal soaps with high melting points and ethylene bisstearamide (these are usually crushed powders) can improve flowability, but lubricity is lower than stearamide with low melting points. Inferior.

  As lubricity with improved flowability, Patent Document 1 discloses that a part of the lubricant is melt-fixed to the iron-base powder, and the lubricant that is melt-fixed to the iron-base powder or the free-base that is not melt-fixed to the iron-base powder. It has been proposed to coat the surface of the lubricant powder with an organosiloxane. Patent Document 2 proposes that a lubricant powder such as zinc stearate or aluminum stearate is melt mixed with an antistatic agent and spray granulated before use. However, these methods are cumbersome because it is necessary to integrate the lubricant powder with other components (organosiloxane, antistatic agent, etc.) prior to the mixing of the lubricant powder and the iron-based powder. Moreover, since it is necessary to integrate (make up) according to the sintered compact item, the inventory increases.

  Patent Document 3 discloses a lubricant having a particle size of 200 μm or less and a crushing strength of 0.2 to 2 MPa. By eliminating the large-diameter lubricant, it is possible to prevent the formation of large voids in the sintered body, and by setting the crushing strength within a predetermined range, the lubricant can be prevented from being pulverized and crushed during compression molding. It is said that the generation of voids in the sintered body can be prevented as possible. However, even with the lubricant of Patent Document 3, it is difficult to achieve both flowability and lubricity at a high level. Note that the lubricant of Patent Document 3 seems to sufficiently exceed 100 ° C. For example, the lubricant of Patent Document 3 is manufactured by heating and melting at 150 to 250 ° C. and then spray drying, and it is described that it takes too much time to melt at less than 150 ° C. Therefore, it is inferred that the melting point is close to 150 ° C. In the examples, a granulated product of stearamide and ethylenebisstearic acid amide is used as a lubricant, and it is described that the melting point of this granulated product was about 111 ° C.

JP 2001-254102 A JP 2004-2964 A JP 2005-307348 A

  The present invention has been made paying attention to the circumstances as described above, and its purpose is to provide a mixed powder for powder metallurgy that exhibits high flowability during transfer and exhibits high lubricity during compacting, And it is providing the sintered compact using this mixed powder.

  As a result of intensive studies to solve the above problems, the present inventors have demonstrated excellent flowability and lubricity by simply mixing these two specific lubricants. The present invention was completed by discovering that aggregation of the agent can be prevented.

That is, the mixed powder for powder metallurgy according to the present invention is characterized in that it includes an iron-based powder and the first lubricant A and the second lubricant B that exhibit the following characteristics.
1) First lubricant A
Melting point: 50-120 ° C.
Average particle diameter D ₅₀ : 20-60 μm,
Circularity of particle projection image: 0.9 or more 2) Second lubricant B
Melting point: 140-250 ° C
Average particle diameter D ₅₀ : 1 to 15 μm

The amount of the lubricant A is, for example, 10 to 50 parts by mass with respect to a total of 100 parts by mass of the lubricant A and the lubricant B. Particle size ratio of the lubricant A and lubricant B (average particle diameter D ₅₀ of the average particle diameter D ₅₀ / lubricant B of lubricant A) is, for example, 2 to 30, the lubricant A and lubricant B The difference in melting point (melting point of lubricant B−melting point of lubricant A) is, for example, 150 ° C. or less. The lubricant A includes R ¹ —CONH—R ² (where R ¹ is a hydrocarbon group having 7 to 29 carbon atoms, and R ² is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms), etc. As the lubricant B, R ³ —CONR ⁴ R ⁵ (wherein R ³ is an alkyl group having 2 to 10 carbon atoms substituted with a plurality of hydroxy groups, and R ⁴ has 8 to 30 carbon atoms). And R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms). The total amount of the lubricant A and the lubricant B is, for example, 0.01 to 2 parts by mass with respect to 100 parts by mass of the iron-based powder. The powder mixture for powder metallurgy may further contain a powder for alloying containing copper, nickel, chromium, molybdenum, phosphorus, sulfur or graphite, and improve characteristics such as manganese sulfide, talc, or calcium fluoride. An agent may be further blended. A sintered body is obtained by compression molding and sintering the powder mixture for powder metallurgy.

  According to the present invention, since two specific lubricants are used, excellent flowability and lubricity can be exhibited simply by mixing, and further, aggregation of the lubricant can be prevented.

  The present invention relates to a powder mixture for powder metallurgy composed of an iron-based powder and a lubricant, and uses at least two lubricants (first lubricant A and second lubricant B) as lubricants. There is a feature in that. The first lubricant A is characterized in that it has a low melting point, a large particle size, and a shape close to a true sphere, and the second lubricant B has a high melting point and a small particle size. There are features. Low melting point, large particle size, true spherical lubricant A contributes mainly to improving lubricity, and high melting point, small particle size lubricant B contributes to improving flowability while maintaining high lubricity. By using together, both lubricity and flowability are improved. More specifically, since the lubricant A has a low melting point, it greatly contributes to improving the lubricity. However, on the other hand, there is a drawback in that the flowability is lowered and the particles tend to aggregate. In the present invention, the lubricant B having a high melting point and a small particle size is sandwiched between the lubricants A having a large particle size to prevent the lubricants A from coming into contact with each other. The contact probability between the lubricants A is reduced, and the aggregation of lubricants can be highly prevented. Further, the flow of the lubricant is prevented by making the lubricant A spherical, thereby improving the flowability, and further, by combining with the lubricant B having a high melting point, the flowability is further enhanced. Details of the lubricant A and the lubricant B are as follows.

(1) Lubricant A
The melting point of the lubricant A is 50 ° C. or higher, preferably 55 ° C. or higher, more preferably 60 ° C. or higher. If the melting point of the lubricant is too low, problems are likely to occur in terms of flowability and aggregation. The upper limit of the melting point can be set as long as the lubricity can be maintained, and is 120 ° C. or lower, preferably 100 ° C. or lower, more preferably 90 ° C. or lower.

The average particle diameter D ₅₀ of the lubricant A is 20 μm or more, preferably 25 μm or more, more preferably 30 μm or more. The larger the particle size, the higher the lubrication effect. However, if the particle size becomes too large, the flowability decreases. Further, the surface of the green compact, the surface crack of the sintered body, or internal defects are likely to occur. Therefore, the average particle diameter D ₅₀ is 60 μm or less, preferably 55 μm or less, more preferably 50 μm or less.

Note the average particle size and D _50, it means a 50% particle size of the cumulative particle size distribution curve (cumulative average diameter) can be measured, for example, using Microtrac particle size distribution apparatus (manufactured by Nikkiso Co. X-100). Among the setting items, “Setting whether to transmit light of sample” is set, setting is not set for “whether it is spherical”, the refractive index is set to 1.81, and the solvent used is set to water. Is recommended. As a sample pretreatment, it is recommended to dilute 0.2 g of the sample with 50 ml of pure water and add a few drops of a surfactant to disperse the sample. Usually, it is measured three times and the average value is adopted.

  The circularity of the lubricant A is 0.9 or more, preferably 0.92 or more, more preferably 0.94 or more. As the circularity of the lubricant A becomes higher, aggregation can be prevented and the flowability becomes higher. The upper limit of the circularity is not particularly set, but may be about 0.98, for example.

More precisely, the degree of circularity means that the circumference L ₁ of an image (particle projection image) obtained by projecting particles perpendicular to a plane is measured, and the circumference L ₂ of a circle having the same area as the particle projection image The value divided by L ₁ (L ₂ / L ₁ , the circularity of the particle projection image). The circularity X ₁ , X ₂ ,... X _n is calculated for _n particles, and the average value ((ΣX _i ) / n, where ΣX _i is the sum of X ₁ to X _n ) Circularity. This circularity can be determined using, for example, a particle shape image analyzer “PITA-1” manufactured by Seishin Corporation.

R ¹ —CONH—R ² (wherein R ¹ is a hydrocarbon group having 7 to 29 carbon atoms and R ² is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms) as a compound that can be used for the lubricant A ) And the like. The R ¹ —CONH—R ² can be regarded formally as a dehydration product of R ¹ COOH and R ² NH ₂ , but may be produced by other methods.

Examples of the hydrocarbon group forming R ¹ include a saturated hydrocarbon group (such as an alkyl group) and an unsaturated hydrocarbon group (such as an alkenyl group and an alkynyl group). The number of unsaturated bonds in the unsaturated hydrocarbon group may be one or plural (for example, about 2 to 6, preferably about 2 to 3). In the case of plural, the number of unsaturated double bonds and unsaturated triple bonds Both may be included. Preferred hydrocarbon groups are alkyl groups, alkenyl groups and the like (particularly alkyl groups). These hydrocarbon groups are preferably linear, but one or more lower alkyl groups (for example, having 1 to 6 carbon atoms, particularly 1 to 1 carbon atoms) in the carbon atoms constituting the straight chain (main chain). An alkyl group of about 3; however, the carbon number of these lower alkyl groups is less than the carbon number of the main chain) may be substituted. The carbon number of the hydrocarbon group is preferably 11 or more (particularly 15 or more) and 25 or less (particularly 23 or less). When the lower alkyl group is substituted, the carbon number of the main chain is, for example, 5 or more, preferably 8 or more, and more preferably 10 or more.

Examples of R ¹ COOH include the following compounds.

[When R ¹ = linear alkyl group]
For example, octanoic acid (caprylic acid), nonanoic acid (pelargonic acid), decanoic acid (capric acid), undecanoic acid, dodecanoic acid (lauric acid), tridecanoic acid, tetradecanoic acid (myristic acid), pentadecanoic acid (pentadecylic acid), Hexadecanoic acid (palmitic acid), heptadecanoic acid (margaric acid), octadecanoic acid (stearic acid), nonadecanoic acid (tuberculostearic acid), icosanoic acid (arachidic acid), heicosanoic acid, docosanoic acid (behenic acid), tricosanoic acid, Examples include tetracosanoic acid.

[When R ¹ = alkyl group substituted by lower alkyl group]
For example, one substituted with a lower alkyl group includes 2-ethylhexanoic acid, 4-propylpentanoic acid, 4-ethylpentanoic acid, 2-methyldecanoic acid, 3-methyldecanoic acid, 4-methyldecanoic acid, and 5-methyldecane. Acid, 6-methyldecanoic acid, 7-methyldecanoic acid, 9-methyldecanoic acid, 6-ethylnonanoic acid, 5-propyloctanoic acid, 3-methylundecanoic acid, 6-propylnonanoic acid, 2-methyldodecanoic acid, 3-methyldodecane Acid, 4-methyldodecanoic acid, 5-methyldodecanoic acid, 11-methyldodecanoic acid, 7-propyldecanoic acid, 2-methyltridecanoic acid, 12-methyltridecanoic acid, 2-methyltetradecanoic acid, 4-methyltetradecane Acid, 13-methyltetradecanoic acid, 14-methylpentadecanoic acid, 2-ethyltetradecanoic acid, 5-methylhexadecanoic acid, 2-propyltetradecanoic acid, 2-ethylhexadecanoic acid, 14-ethylhexadecanoic acid, 14-methylheptadecanoic acid, 15-methylheptadecanoic acid, 16-methylheptadecanoic acid, 2-butyl Tetradecanoic acid, 2-methyloctadecanoic acid, 3-methyloctadecanoic acid, 4-methyloctadecanoic acid, 5-methyloctadecanoic acid, 6-methyloctadecanoic acid, 7-methyloctadecanoic acid, 8-methyloctadecanoic acid, 9-methyloctadecanoic acid 10-methyloctadecanoic acid, 11-methyloctadecanoic acid, 14-methyloctadecanoic acid, 15-methyloctadecanoic acid, 16-methyloctadecanoic acid, 17-methyloctadecanoic acid, 15-ethylpentadecanoic acid, 3-methylnonadecanoic acid, 2- Ethyl octade Acid, 2-methylicosanoic acid, 2-propyloctadecanoic acid, 2-butyloctadecanoic acid, 2-methyldocosanoic acid, 10-methyldocosanoic acid, 2-pentyloctadecanoic acid, 2-methyltricosanoic acid, 3-methyltricosanoic acid, Examples include 22-methyltricosanoic acid, 20-ethyldocosanoic acid, 18-propylhexicosanoic acid, 2-hexyloctadecanoic acid, and 12-hexyloctadecanoic acid.

  Examples of the substituted lower alkyl group include 2-butyl-5-methylpentanoic acid, 2-isobutyl-5-methylpentanoic acid, 2,3-dimethylnonanoic acid, 4,8-dimethylnonanoic acid, 2- Butyl-5-methylhexanoic acid, 4,4-dimethyldecanoic acid, 2-ethyl-3-methylnonanoic acid, 2,2-dimethyl-4-ethyloctanoic acid, 2-propyl-3-methylnonanoic acid, 2,2- Dimethyldodecanoic acid, 2,3-dimethyldodecanoic acid, 4,10-dimethyldodecanoic acid, 2-butyl-3-methylnonanoic acid, 2-butyl-2-ethylnonanoic acid, 3-ethyl-3-butylnonanoic acid, 4-ptyl -4-ethylnonanoic acid, 3,7,11-trimethyldodecanoic acid, 2,2-dimethyltetradecanoic acid, 3,3-dimethyltetradecanoic acid, 4,4-dimethylteto Decanoic acid, 2-butyl-2-pentylheptanoic acid, 2,3-dimethyltetradecanoic acid, 4,8,12-trimethyltridecanoic acid, 14,14-dimethylpentadecanoic acid, 3-methyl-2-heptylnonanoic acid, 2 , 2-dipentylheptanoic acid, 2,2-dimethylhexadecanoic acid, 2-octyl-3-methylnonanoic acid, 2,3-dimethylheptadecanoic acid, 2,2-dimethyloctadecanoic acid, 2,3-dimethyloctadecanoic acid, 2 , 4-dimethyloctadecanoic acid, 3,3-dimethyloctadecanoic acid, 2-butyl-2-heptylnonanoic acid, 20,20-dimethylhenicosanoic acid and the like.

[When R ¹ = alkenyl group]
Examples of one unsaturated bond include 2-octenoic acid, 3-octenoic acid, 2-nonenoic acid, 3-nonenoic acid, 2-decenoic acid, 4-decenoic acid, 9-decenoic acid and 9-hendenecene. Acid, 10-hendecenoic acid, 2-dodecenoic acid, 3-dodecenoic acid, 5-dodecenoic acid, 11-dodecenoic acid, 2-tridecenoic acid, 12-tridecenoic acid, 4-tetradecenoic acid, 5-tetradecenoic acid, 9-tetradecene Acid, 2-pentadecenoic acid, 14-pentadecenoic acid, 2-hexadecenoic acid, 7-hexadecenoic acid, 9-hexadecenoic acid, 2-heptadecenoic acid, 6-octadecenoic acid, 9-octadecenoic acid, 11-octadecenoic acid, 9-icosene An acid, 11-icosenoic acid, erucic acid, 11-docosenoic acid, 13-docosenoic acid, 15-tetracosenoic acid, etc. are mentioned.

  Examples of those having a plurality of unsaturated bonds include trans-8, trans-12-octadecadienoic acid, cis-9, cis-12-octadecadienoic acid, trans-9, trans-12-octadecadienoic acid. Cis-9, trans-11-octadecadienoic acid, trans-10, cis-12-octadecadienoic acid, cis-9, cis-12-octadecadienoic acid, cis-10, cis-12-octadeca Dienoic acid, trans-10, trans-12-octadecadienoic acid, trans-9, trans-11-octadecadienoic acid, trans-8, trans-10-octadecadienoic acid, trans-9, trans-11- Octadecadienoic acid, cis-9, trans-11, trans-13-octadeca Lienic acid, trans-9, trans-11, trans-13-octadecatrienoic acid, cis-9, cis-11, trans-13-octadecatrienoic acid, cis-9, cis-12, cis-15-octa Decatrienoic acid, trans-9, trans-12, trans-15-octadecatrienoic acid, trans-10, trans-12, trans-14-octadecatrienoic acid, 9,11,13,15-octadecatetraene Acid, 2,2-dimethyl cis-9, cis-12-octadecadienoic acid, 8,11,14-icosatrienoic acid, 12,20-henicosadienoic acid, 9,13-docosadienoic acid, 4,8,12, 15,19-docosapentaenoic acid, 2,2-dimethyl-cis-11, cis-14-icosadie Acid, 9,15-tetracosadenoic acid, 5,8,11-icosatrienoic acid, 7,10,13-docosatrienoic acid, 8,11,14-docosatrienoic acid, 4,8,11,14-hexadecatetraenoic acid 6,9,12,15-hexadecatetraenoic acid, 4,8,12,15-octadecatetraenoic acid, 9,11,13,15-octadecatetraenoic acid, 4,8,12, 16-icosatetraenoic acid, 5,8,11,14-icosatetraenoic acid, 4,7,10,13-docosahexenoic acid, 4,8,12,15,18-icosapentaenoic acid, 4,8,12,15, And 19-docosapentaenoic acid.

  Examples of the substituted lower alkyl group include 2-methyl-2-heptenoic acid, 3-methyl-2-nonenoic acid, 5-methyl-2-nonenoic acid, 5-methyl-2-undecenoic acid, 2 -Methyl-2-dodecenoic acid, 5-methyl-2-tridecenoic acid, 2-methyl-9-octadecenoic acid, 2-ethyl 9-octadecenoic acid, 2-propyl-9-octadecenoic acid, 2-methyl-2-icosene Acid, 2-methyl-2-hexacosenoic acid, 3,4-dimethyl-3-pentenoic acid, 5,9-dimethyl-2-decenoic acid, 2,5-dimethyl-2-heptadecenoic acid, 2,2-dimethyl- Examples include 11-icosenoic acid.

[When R ¹ = alkynyl group]
One or a plurality of unsaturated bonds may be substituted, and a lower alkyl group may be substituted. For example, 2-octynic acid, 7-octynic acid, 2-nonic acid, 2-decynic acid, 2-undecylic acid, 6 -Undecylic acid, 9-undecylic acid, 10-undecylic acid, 6-dodecylic acid, 7-dodecylic acid, 8-tridecylic acid, 9-tridecynoic acid, 7-tetradecynoic acid, 7-hexadesinic acid, 2-heptadesinic acid, 5-octadesinic acid, 6-octadesinic acid, 7-octadesinic acid, 8-octadesinic acid, 9-octadesinic acid, 10-octadesinic acid, 11-octadesinic acid, 9-nonadecic acid, 12-nonadecic acid, 12-octadesinic acid, 13-docosinic acid, 11,16-docosadiic acid, 7,15-docosadiic acid, 8,15-docosadiic acid, 21-tricosic acid, 22 Such as Torikoshin acid, and the like.

R ² can be selected from a wider range than R ¹ . R ² can be widely selected from, for example, a linear hydrocarbon group and a branched chain hydrocarbon group, and may be a hydrogen atom, and is preferably a hydrocarbon group (particularly a linear hydrocarbon group). Examples of the hydrocarbon group forming R ² include a saturated hydrocarbon group (alkyl group) and an unsaturated hydrocarbon group (alkenyl group, alkynyl group, etc.). The number of carbons is preferably 5 to 26, particularly about 12 to 24.

Examples of R ² NH ₂ include the following compounds.

[When R ² = linear alkyl group]
For example, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine (stearylamine), nonadecylamine, icosylamine, hencicosyl Luamine, docosylamine, tricosylamine, tetracosylamine and the like can be mentioned.

[When R ² = alkyl group substituted by lower alkyl group]
For example, as one substituted with a lower alkyl group, for example, 2-ethylhexylamine, 4-propylpentylamine, 4-ethylpentylamine, 2-methyldecylamine, 3-methyldecylamine, 4-methyldecylamine 5-methyldecylamine, 6-methyldecylamine, 7-methyldecylamine, 9-methyldecylamine, 6-ethylnonylamine, 5-propyloctylamine, 3-methylundecylamine, 6-propylnonylamine, 2-methyldodecylamine, 3-methyldodecylamine, 4-methyldodecylamine, 5-methyldodecylamine, 11-methyldodecylamine, 7-propyldecylamine, 2-methyltridecylamine, 12-methyltridecylamine, 2-methyltetradecylamine, 4-methyl Tetradecylamine, 13-methyltetradecylamine, 14-methylpentadecylamine, 2-ethyltetradecylamine, 15-methylhexadecylamine, 2-propyltetradecylamine, 2-ethylhexadecylamine, 14-ethylhexaamine Decylamine, 14-methylheptadecylamine, 15-methylheptadecylamine, 16-methylheptadecylamine, 2-butyltetradecylamine, 2-methyloctadecylamine, 3-methyloctadecylamine, 4-methyloctadecylamine, 5-methyl Octadecylamine, 6-methyloctadecylamine, 7-methyloctadecylamine, 8-methyloctadecylamine, 9-methyloctadecylamine, 10-methyloctadecylamine, 11-methyloctadecylamine 14-methyloctadecylamine, 15-methyloctadecylamine, 16-methyloctadecylamine, 17-methyloctadecylamine, 15-ethylpentadecylamine, 3-methylnonadecylamine, 2-ethyloctadecylamine, 2-methyloctylamine Cosylamine, 2-propyloctadecylamine, 2-butyloctadecylamine, 2-methyldocosylamine, 10-methyldocosylamine, 2-pentyloctadecylamine, 2-methyltricosylamine, 3-methyltricosylamine, 22-methyl Examples include tricosylamine, 20-ethyldocosylamine, 18-propylhexicosylamine, 2-hexyloctadecylamine, 12-hexyloctadecylamine and the like.

  Examples of those substituted with a plurality of lower alkyl groups include 2-butyl-5-methylpentylamine, 2-isobutyl-5-methylpentylamine, 2,3-dimethylnonylamine, 4,8-dimethylnonylamine, 2 -Butyl-5-methylhexylamine, 4,4-dimethyldecylamine, 2-ethyl-3-methylnonylamine, 2,2-dimethyl-4-ethyloctylamine, 2-propyl-3-methylnonylamine, 2 , 2-dimethyldodecylamine, 2,3-dimethyldodecylamine, 4,10-dimethyldodecylamine, 2-butyl-3-methylnonylamine, 2-butyl-2-ethylnonylamine, 3-ethyl-3-butyl Nonylamine, 4-butyl-4-ethylnonylamine, 3,7,11-trimethyldodecylamine, 2,2- Methyltetradecylamine, 3,3-dimethyltetradecylamine, 4,4-dimethyltetradecylamine, 2-butyl-2-pentylheptylamine, 2,3-dimethyltetradecylamine, 4,8,12-trimethyltridecyl Amine, 14,14-dimethylpentadecylamine, 3-methyl-2-heptylnonylamine, 2,2-dipentylheptylamine, 2,2-dimethylhexadecylamine, 2-octyl-3-methylnonylamine, 2, 3-dimethylheptadecylamine, 2,2-dimethyloctadecylamine, 2,3-dimethyloctadecylamine, 2,4-dimethyloctadecylamine, 3,3-dimethyloctadecylamine, 2-butyl-2-heptylnonylamine, 20 , 20-dimethylhenicosylamine etc. It is below.

[When R ² = alkenyl group]
Examples of one unsaturated bond include 2-octenylamine, 3-octenylamine, 2-nonenylamine, 2-nonenylamine, 2-decenylamine, 4-decenylamine, 9-decenylamine, 9-hendecenylamine, 10 -Hendecenylamine, 2-dodecenylamine, 3-dodecenylamine, 5-dodecenylamine, 11-dodecenylamine, 2-tridecenylamine, 12-tridecenylamine, 4-tetradecenylamine, 5-tetradecenylamine, 9- Tetradecenylamine, 2-pentadecenylamine, 14-pentadecenylamine, 2-hexadecenylamine, 7-hexadecenylamine, 9-hexadecenylamine, 2-heptadecenylamine, 6-octa Decenylamine, 9-octadecenylamine (Ole Triethanolamine), 11-octadecenylamine, 9 Ikoseniruamin, 11- Ikoseniruamin, 11- Dokoseniruamin, 13 Dokoseniruamin, such as 15-tetracosenoylamino cycloalkenyl amines.

  Examples of the compound having a plurality of unsaturated bonds include trans-8, trans-10-octadecadienylamine, cis-9, cis-12-octadecadienylamine, trans-9, trans-12-octadeca. Dienylamine, cis-9, trans-11-octadecadienylamine, trans-10, cis-12-octadecadienylamine, cis-9, cis-12-octadecadienylamine, cis-10, cis-12-octadecadienylamine, trans-10, trans-12-otakudecadienylamine, trans-9, trans-11-octadecadienylamine, trans-8, trans-10-octadecadienyl Amine, trans-9, trans-11-octadecadienyl Min, cis-9, trans-11, trans-13-octadecatrienylamine, trans-9, trans-11, trans-13-octadecatrienylamine, cis-9, cis-12, cis-15- Octadecatrienylamine, trans-9, trans-12, trans-15-octadecatrienylamine, trans-10, trans-12, trans-14-otatadecatrienylamine, 9, 11, 13, 15- Octadecatetraenylamine, 2,2-dimethylcis-9, cis-12-octadecadienylamine, 8,11,14-icosatrienylamine, 12,20-henicosadienylamine, 9,13 -Docosadienylamine, 4,8,12,15,19-docosapentaeni Amine, 2,2-dimethyl-cis-11, cis-14-icosadienylamine, 9,15-tetracosadienylamine, 5,8,11-icosatrienylamine, 7,10,13-docosatri Enylamine, 8,11,14-docosatrienylamine, 4,8,11,14-hexadecatetraenylamine, 6,9,12,15-hexadecatetraenylamine, 4,8,12, 15-octadecatetraenylamine, 9,11,13,15-octadecatetraenylamine, 4,8,12,16-icosatetraenylamine, 5,8,11,14-icosatetraenylamine, 4,7,10,13-docosahexaenylamine, 4,8,12,15,18-icosapentaenylamine, 4,8,12,15,19-docosapentaenylenyl Min etc. are mentioned.

  Examples of the substituted lower alkyl group include 2-methyl-2-heptenylamine, 3-methyl-2-nonenylamine, 5-methyl-2-nonenylamine, 5-methyl-2-undecenylamine, and 2-methyl. 2-dodecenylamine, 5-methyl-2-tridecenylamine, 2-methyl-9-octadecenylamine, 2-ethyl-9-octadecenylamine, 2-propyl-9-octadecenylamine, 2-methyl -2-icosenylamine, 5,9-dimethyl-2-decenylamine, 2,5-dimethyl-2-heptadecenylamine, 2,2-dimethyl-11-icocenylamine and the like.

[When R ² = alkynyl group]
The number of unsaturated bonds may be one or more, and a lower alkyl group may be substituted. For example, 2-octynylamine, 7-octynylamine, 2-noninylamine, 2-decynylamine, 2-undecynylamine, 6-undecynine Ruamine, 9-undecynylamine, 10-undecynylamine, 6-dodecynylamine, 7-dodecynylamine, 8-tridecynylamine, 9-tridecynylamine, 7-tetradecynylamine, 7-hexadecynylamine, 2 -Heptadecynylamine, 5-octadecynylamine, 6-octadecynylamine, 7-octadecynylamine, 8-octadecynylamine, 9-octadecynylamine, 10-octadecynylamine, 11- Octadecynylamine, 9-nonadecynylamine, 12-nonadecynylamine, Examples include 2-octadecynylamine, 13-docosinylamine, 11,16-docosadiynylamine, 7,15-docosadiynylamine, 8,15-docosadiynylamine, 21-tricosynylamine, and 22-tricosynylamine. .

Particularly preferred R ¹ —CONH—R ² is an alkane or alkene carboxylic acid having about 14 to 24 carbon atoms (particularly about 16 to 22 carbon atoms) and a monoalkane having about 16 to 22 carbon atoms (particularly about 18 carbon atoms). Alternatively, it is an amide composed of monoalkeneamine. R ¹ —CONH—R ² is more preferably an amide in which one of a hydrocarbon group derived from a carboxylic acid and a hydrocarbon group derived from an amine is a saturated hydrocarbon group and the other is an unsaturated hydrocarbon group. For example, (N-octadecenyl) hexadecanoic acid amide (N-oleyl palmitoamide and the like), (N-octadecyl) docosenoic acid amide (N-stearyl erucamide and the like) and the like.

The circularity of the lubricant A is adjusted using a spray drying method. For example, the lubricant A is heated and melted. The heating temperature is about 20 to 30 ° C. higher than the melting point of the lubricant A, and specifically can be set in the range of about 80 to 150 ° C. The obtained liquid is guided to a spray nozzle with a metering pump and sprayed into the space from the nozzle together with appropriately heated air, thereby being recovered as particles having a constant particle size. The spray amount, air temperature, and air pressure are adjusted according to the desired particle size, but in the case of the Okawahara Koki twin jet nozzle RJ-25 nozzle, the spray air temperature is 250 ° C., the spray air pressure is 0.1 to 0.2 MPa, the spray amount Under the condition of 20 to 80 kg / h, particles having an average particle diameter D ₅₀ of 20 to ₅₀ μm and a circularity of 0.95 are obtained. There is also a method of obtaining particles with high circularity with a high-pressure spray nozzle that does not use air. For example, particles having an average particle diameter D ₅₀ of 20 to ₅₀ μm and a circularity of 0.95 are obtained under the conditions of an inner diameter of 0.1 mm, a spray pressure of 10 MPa, and a spray amount of 10 to 30 kg / h.

  In addition, when preparing the lubricant A having a predetermined particle diameter, classification may be performed as necessary. The classification may be any of wet classification, dry classification, and sieving classification. While wet classification has the advantage of excellent classification accuracy, it has the disadvantage that the dispersion medium needs to be removed after classification, resulting in high costs.

  The dry classification may be any of gravity classification, inertia classification, and centrifugal classification. Inertial classification and centrifugal classification have excellent classification accuracy.

  Since sieving classification is performed using the size of the stitches, classification accuracy is high. However, depending on the type of the lubricant A, it may remarkably adhere to the stitches, so that classification accuracy and processing efficiency may be reduced.

(2) Lubricant B
The melting point of the lubricant B is 140 ° C. or higher, preferably 145 ° C. or higher, more preferably 150 ° C. or higher. By increasing the melting point of the lubricant B, the flowability can be improved, and it helps to prevent the aggregation of the lubricant A. However, if the melting point of the lubricant B is too high, it adversely affects the lubricity. Therefore, the melting point of the lubricant B is 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 170 ° C. or lower.

The average particle diameter D ₅₀ of the lubricant B is 15 μm or less, preferably 10 μm or less, more preferably 5 μm or less. By reducing the particle size of the lubricant B, the aggregation of the lubricant A can be prevented. The lower limit of the average particle diameter D ₅₀ of the lubricant B can be set within a range that can be easily achieved, and is 1 μm or more, preferably 1.5 μm or more.

The average particle diameter D ₅₀ of the lubricant B may be prepared by classification in the same manner as the lubricant A. The average particle diameter D ₅₀ of the lubricant B can be measured in the same manner as the average particle diameter D ₅₀ of the lubricant A.

Examples of the compound that can be used for the lubricant B include alkylene bis fatty acid amides (for example, C _2-4 alkylene bis C _14-30 fatty acid amide such as ethylene _{bisstearamide} ), R ³ —CONR ⁴ R ⁵ (however, R ³ is an alkyl group having 2 to 10 carbon atoms substituted by a plurality of hydroxy groups, R ⁴ is a hydrocarbon group having 8 to 30 carbon atoms, and R ⁵ is a hydrogen atom or a hydrocarbon having 1 to 30 carbon atoms. Group). R ³ —CONR ⁴ R ⁵ can be regarded formally as a dehydration product of R ³ COOH and R ⁴ R ⁵ NH, but may be produced by other methods.

The number of carbon atoms of the alkyl group of R ³ is, for example, about 2 to 10 (preferably 4 to 6 carbon atoms, particularly 5). The number of carbon atoms in the alkyl group represented by R ³ may be determined according to the number n of hydroxyl groups substituted on the alkyl group. For example, the number is n or more and 5 × n or less (preferably 3 × n or less, particularly 2. 5 × n or less), and particularly preferably equal to the number n of substituted hydroxyl groups.

The number n of the hydroxyl groups is, for example, 2 or more (preferably 3 or more, more preferably 4 or more). The upper limit of the number n of the hydroxyl groups is naturally limited by the number of carbon atoms of R ³ , but is, for example, about 10 or less (preferably 8 or less, more preferably 6 or less), and may be 5.

As the number n of hydroxyl groups increases and the number of carbon atoms of R ³ decreases relative to the number n of hydroxyl groups, the interaction between the R ³ portion and the metal powder becomes stronger.

Preferable R ³ COOH includes aldonic acid. Aldonic acid is a polyhydroxycarboxylic acid corresponding to a compound obtained by oxidizing an aldehyde group of aldose to form a carboxyl group, and examples thereof include compounds represented by the following formula.
HOOC- (CHOH) _m -CH ₂ OH
(In the formula, m represents a natural number, preferably 1 to 9, more preferably 3 to 5, particularly 4.)

  Examples of the aldonic acid include glyceric acid, erythronic acid, threonic acid, ribbon acid, arabinonic acid, xylonic acid, lyxonic acid, alonic acid, altronic acid, gluconic acid, mannonic acid, gulonic acid, indian acid, galactonic acid, Examples include taronic acid.

R ⁴ can be preferably selected from the same range as R ¹ . The longer the carbon number, the better the fluidity and lubricity. However, if the carbon number is too long, fluidity and lubricity are lowered.

R ⁵ can be preferably selected from the same range as R ² . Particularly preferred R ⁵ is a hydrogen atom.

Examples of R ⁴ R ⁵ NH include the following compounds.

[When R ⁴ = linear alkyl group and R ⁵ = hydrogen atom]
For example, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, nonadecylamine, icosylamine, heicosylamine, docosylamine, Examples include tricosylamine and tetracosylamine.

[When R ⁴ = alkyl group substituted by a lower alkyl group, R ⁵ = hydrogen atom]
For example, one substituted with a lower alkyl group includes 2-ethylhexylamine, 4-propylpentylamine, 4-ethylpentylamine, 2-methyldecylamine, 3-methyldecylamine, 4-methyldecylamine, 5 -Methyldecylamine, 6-methyldecylamine, 7-methyldecylamine, 9-methyldecylamine, 6-ethylnonylamine, 5-propyloctylamine, 3-methylundecylamine, 6-propylnonylamine, 2- Methyldodecylamine, 3-methyldodecylamine, 4-methyldodecylamine, 5-methyldodecylamine, 11-methyldodecylamine, 7-propyldecylamine, 2-methyltridecylamine, 12-methyltridecylamine, 2- Methyltetradecylamine, 4-methyltetra Silamine, 13-methyltetradecylamine, 14-methylpentadecylamine, 2-ethyltetradecylamine, 15-methylhexadecylamine, 2-propyltetradecylamine, 2-ethylhexadecylamine, 14-ethylhexadecylamine 14-methylheptadecylamine, 15-methylheptadecylamine, 16-methylheptadecylamine, 2-butyltetradecylamine, 2-methyloctadecylamine, 3-methyloctadecylamine, 4-methyloctadecylamine, 5-methyloctadecylamine 6-methyloctadecylamine, 7-methyloctadecylamine, 8-methyloctadecylamine, 9-methyloctadecylamine, 10-methyloctadecylamine, 11-methyloctadecylamine, 1 -Methyloctadecylamine, 15-methyloctadecylamine, 16-methyloctadecylamine, 17-methyloctadecylamine, 15-ethylpentadecylamine, 3-methylnonadecylamine, 2-ethyloctadecylamine, 2-methylicosylamine, 2-propyloctadecylamine, 2-butyloctadecylamine, 2-methyldocosylamine, 10-methyldocosylamine, 2-pentyloctadecylamine, 2-methyltricosylamine, 3-methyltricosylamine, 22-methyltricosylamine, Examples thereof include 20-ethyldocosylamine, 18-propylhexicosylamine, 2-hexyloctadecylamine, 12-hexyloctadecylamine and the like.

  Examples of those substituted with a plurality of lower alkyl groups include 2-butyl-5-methylpentylamine, 2-isobutyl-5-methylpentylamine, 2,3-dimethylnonylamine, 4,8-dimethylnonylamine, 2-butyl -5-methylhexylamine, 4,4-dimethyldecylamine, 2-ethyl-3-methylnonylamine, 2,2-dimethyl-4-ethyloctylamine, 2-propyl-3-methylnonylamine, 2,2 -Dimethyldodecylamine, 2,3-dimethyldodecylamine, 4,10-dimethyldodecylamine, 2-butyl-3-methylnonylamine, 2-butyl-2-ethylnonylamine, 3-ethyl-3-butylnonylamine 4-butyl-4-ethylnonylamine, 3,7,11-trimethyldodecylamine, 2,2-dimethyl Tradecylamine, 3,3-dimethyltetradecylamine, 4,4-dimethyltetradecylamine, 2-butyl-2-pentylheptylamine, 2,3-dimethyltetradecylamine, 4,8,12-trimethyltridecyl Amine, 14,14-dimethylpentadecylamine, 3-methyl-2-heptylnonylamine, 2,2-dipentylheptylamine, 2,2-dimethylhexadecylamine, 2-octyl-3-methylnonylamine, 2, 3-dimethylheptadecylamine, 2,2-dimethyloctadecylamine, 2,3-dimethyloctadecylamine, 2,4-dimethyloctadecylamine, 3,3-dimethyloctadecylamine, 2-butyl-2-heptylnonylamine, 20 , 20-dimethylhenicosylamine .

[When R ⁴ = alkenyl group and R ⁵ = hydrogen atom]
Examples of one unsaturated bond include 2-octenylamine, 3-octenylamine, 2-nonenylamine, 2-nonenylamine, 2-decenylamine, 4-decenylamine, 9-decenylamine, 9-hendecenylamine, 10 -Hendecenylamine, 2-dodecenylamine, 3-dodecenylamine, 5-dodecenylamine, 11-dodecenylamine, 2-tridecenylamine, 12-tridecenylamine, 4-tetradecenylamine, 5-tetradecenylamine, 9- Tetradecenylamine, 2-pentadecenylamine, 14-pentadecenylamine, 2-hexadecenylamine, 7-hexadecenylamine, 9-hexadecenylamine, 2-heptadecenylamine, 6-octa Decenylamine, 9-octadecenylamine, 11 Octadecenyl amine, 9- Ikoseniruamin, 11- Ikoseniruamin, 11- Dokoseniruamin, 13 Dokoseniruamin, such as 15-tetracosenoylamino cycloalkenyl amines.

  Examples of the compound having a plurality of unsaturated bonds include trans-8, trans-10-octadecadienylamine, cis-9, cis-12-octadecadienylamine, trans-9, trans-12-octadeca. Dienylamine, cis-9, trans-11-octadecadienylamine, trans-10, cis-12-octadecadienylamine, cis-9, cis-12-octadecadienylamine, cis-10, cis-12-octadecadienylamine, trans-10, trans-12-otakudecadienylamine, trans-9, trans-11-octadecadienylamine, trans-8, trans-10-octadecadienyl Amine, trans-9, trans-11-octadecadienyl Min, cis-9, trans-11, trans-13-octadecatrienylamine, trans-9, trans-11, trans-13-octadecatrienylamine, cis-9, cis-12, cis-15- Octadecatrienylamine, trans-9, trans-12, trans-15-octadecatrienylamine, trans-10, trans-12, trans-14-otatadecatrienylamine, 9, 11, 13, 15- Octadecatetraenylamine, 2,2-dimethylcis-9, cis-12-octadecadienylamine, 8,11,14-icosatrienylamine, 12,20-henicosadienylamine, 9,13 -Docosadienylamine, 4,8,12,15,19-docosapentaeni Amine, 2,2-dimethyl-cis-11, cis-14-icosadienylamine, 9,15-tetracosadienylamine, 5,8,11-icosatrienylamine, 7,10,13-docosatri Enylamine, 8,11,14-docosatrienylamine, 4,8,11,14-hexadecatetraenylamine, 6,9,12,15-hexadecatetraenylamine, 4,8,12, 15-octadecatetraenylamine, 9,11,13,15-octadecatetraenylamine, 4,8,12,16-icosatetraenylamine, 5,8,11,14-icosatetraenylamine, 4,7,10,13-docosahexaenylamine, 4,8,12,15,18-icosapentaenylamine, 4,8,12,15,19-docosapentaenylenyl Min etc. are mentioned.

  Examples of the substituted lower alkyl group include 2-methyl-2-heptenylamine, 3-methyl-2-nonenylamine, 5-methyl-2-nonenylamine, 5-methyl-2-undecenylamine, and 2-methyl. 2-dodecenylamine, 5-methyl-2-tridecenylamine, 2-methyl-9-octadecenylamine, 2-ethyl-9-octadecenylamine, 2-propyl-9-octadecenylamine, 2-methyl -2-icosenylamine, 5,9-dimethyl-2-decenylamine, 2,5-dimethyl-2-heptadecenylamine, 2,2-dimethyl-11-icocenylamine and the like.

[When R ⁴ = alkynyl group and R ⁵ = hydrogen atom]
The number of unsaturated bonds may be one or more, and a lower alkyl group may be substituted. For example, 2-octynylamine, 7-octynylamine, 2-noninylamine, 2-decynylamine, 2-undecynylamine, 6-undecynine Ruamine, 9-undecynylamine, 10-undecynylamine, 6-dodecynylamine, 7-dodecynylamine, 8-tridecynylamine, 9-tridecynylamine, 7-tetradecynylamine, 7-hexadecynylamine, 2 -Heptadecynylamine, 5-octadecynylamine, 6-octadecynylamine, 7-octadecynylamine, 8-octadecynylamine, 9-octadecynylamine, 10-octadecynylamine, 11- Octadecynylamine, 9-nonadecynylamine, 12-nonadecynylamine, Examples include 2-octadecynylamine, 13-docosinylamine, 11,16-docosadiynylamine, 7,15-docosadiynylamine, 8,15-docosadiynylamine, 21-tricosynylamine, and 22-tricosynylamine. .

Particularly preferred examples of R ³ —CONR ⁴ R ⁵ include (N-long chain alkyl) aldonic acid amides and (N-long chain alkenyl) aldonic acid amides, such as compounds represented by the following formulae.

[Wherein, p represents an integer of 1 to 9 (preferably 1 to 4), and q represents an integer of 7 to 29 (preferably 11 to 23, more preferably 15 to 21). a, b and c are all integers (preferably b = 1), and a + b + c = q. ]

R ³ —CONR ⁴ R ⁵ can be produced by various methods, but it is convenient to use an amidation reaction using R ³ COOH or an equivalent thereof and R ⁴ R ⁵ NH as raw materials. R ³ COOH and R ⁴ R ⁵ NH can be amidated by, for example, dehydration condensation. As equivalents, acid halides, esters (including lactone forms), and the like can be used. In particular, when R ³ COOH is aldonic acid, ring-closed forms (lactone forms) are relatively often used. Examples of the lactone form of aldonic acid include γ-gluconolactone, δ-gluconolactone, γ-galactolactone, and the like.

  The ratio of the lubricant A is, for example, 10 parts by mass or more, preferably 15 parts by mass or more, and more preferably 20 parts by mass or more with respect to 100 parts by mass of the total of the lubricant A and the lubricant B. Lubricating property can be secured by using a predetermined amount or more of the lubricant A. However, if the ratio of the lubricant A becomes excessive and the ratio of the lubricant B becomes too small, the fluidity improving effect and the aggregation preventing effect by the lubricant B are insufficient. Therefore, the ratio of the lubricant A is, for example, 50 parts by mass or less, preferably 40 parts by mass or less, and more preferably 35 parts by mass or less with respect to 100 parts by mass in total of the lubricant A and the lubricant B.

In order to use the lubricant A and the lubricant B most effectively, it is desirable that the relative relationship between them is as follows, for example. That (average particle diameter D ₅₀ of the average particle diameter D ₅₀ / lubricant B of lubricants A) particle size ratio of the lubricant A and lubricant B is, for example, about 2 to 30, preferably about 5 to 25, further Preferably it is about 10-20. The difference between the melting points of the lubricant A and the lubricant B (the melting point of the lubricant B−the melting point of the lubricant A) is, for example, 150 ° C. or less, preferably 120 ° C. or less, more preferably 110 ° C. or less.

(3) Other Lubricants, etc. In the present invention, the present invention is not limited to the lubricant A and the lubricant B, and other lubricants C can be used in combination. Other lubricants C include metal soaps, alkylene bis fatty acid amides, fatty acids and the like. The metal soap contains a fatty acid salt, for example, a fatty acid salt having 12 or more carbon atoms (preferably about 14 to 24), and usually zinc stearate can be used. Examples of the alkylene bis fatty acid amide include C _2-6 alkylene bis C _12-24 carboxylic acid amide, and ethylene bisstearyl amide can be usually used. As this fatty acid, the compound illustrated as said R < ¹ > COOH can be used, for example, These compounds can be used individually or in combination of 2 or more types. The preferable range of the fatty acid is the same as that of the R ¹ COOH, and the particularly preferable fatty acid is a fatty acid having about 16 to 22 carbon atoms. Particularly preferred fatty acids are aliphatic saturated monocarboxylic acids.

  Other lubricants C can be used within a range that does not impair the effects of the lubricants A and B, and the amount of the lubricant C when the entire lubricant is 100 parts by weight is, for example, 50 parts by weight or less, preferably Is 20 parts by mass or less, more preferably 10 parts by mass or less. The amount of the lubricant A when the entire lubricant is 100 parts by mass is, for example, about 5 to 45 parts by mass, preferably about 10 to 35 parts by mass, and more preferably about 15 to 30 parts by mass.

(4) Iron-based powder The lubricants A and B are used as a mixed powder for powder metallurgy in combination with an iron-based powder. The iron-based powder may be either pure iron powder or iron alloy powder. The iron alloy powder may be a partial alloy powder in which an alloy powder (copper, nickel, chromium, molybdenum, etc.) is diffusely adhered to the surface of the iron-based powder, and is obtained from molten iron (or molten steel) containing an alloy component. Pre-alloyed powder may be used. The iron-based powder is usually produced by atomizing molten iron (or steel). Further, the iron-based powder may be reduced iron powder produced by reducing iron ore or mill scale.

  The average particle diameter of the iron-based powder is, for example, 40 to 120 μm, preferably 50 to 100 μm, and more preferably 60 to 80 μm. The measurement method of the average particle size of the iron-based powder is a particle having a cumulative sieving amount of 50% when the particle size distribution is measured in accordance with Japan Powder Metallurgy Industry Association Standard JPMA P 02-1992 (Metal powder sieving analysis test method). The diameter was calculated.

  The total amount of the lubricant A and the lubricant B is, for example, about 0.01 to 2 parts by mass, preferably 0.1 to 1.5 parts by mass, and more preferably 0.001 parts by mass with respect to 100 parts by mass of the iron-based powder. It is 2-1.0 mass part.

(5) Other components The mixed powder for powder metallurgy according to the present invention is optionally mixed with a powder for alloying (powder containing copper, nickel, chromium, molybdenum, phosphorus, sulfur or graphite; for example, copper powder, nickel Powder, chromium powder, molybdenum powder, phosphorus alloy powder, sulfur-containing powder, graphite powder, etc.) and property improvers (manganese sulfide used to improve machinability, talc, calcium fluoride, etc.) It may be. These can be used alone or in appropriate combination.

Mix iron-base powder (especially pure iron powder) and alloying powder (copper powder, nickel powder, chromium powder, molybdenum powder, phosphorus, sulfur, etc.), or iron-base powder and property improvers (manganese sulfide, talc, When mixing calcium fluoride etc.), the usage-amount of each component with respect to 100 mass parts of iron-based iron powder is as follows, for example.
Copper powder: 0.1 to 10 parts by mass (preferably 1 to 4 parts by mass)
Nickel powder: 0.1 to 10 parts by mass (preferably 0.5 to 4 parts by mass)
Chrome alloy powder: 0.1 to 8 parts by mass (preferably 0.2 to 5 parts by mass)
Molybdenum powder: 0.1 to 5 parts by mass (preferably 0.2 to 3 parts by mass)
Phosphorus: 0.01 to 3 parts by mass (preferably 0.05 to 1 part by mass)
Sulfur: 0.01-2 parts by mass (preferably 0.03-1 parts by mass)
Manganese sulfide: 0.05-3 parts by mass (preferably 0.1-1 parts by mass)
Talc: 0.05-3 parts by mass (preferably 0.1-1 parts by mass)
Calcium fluoride: 0.05-3 parts by mass (preferably 0.1-1 parts by mass)

  The mixed powder for powder metallurgy of the present invention may contain a binder in order to prevent segregation and dust generation. The usage-amount of a binder is about 0.01-0.3 mass part with respect to 100 mass parts of iron-based powders, Preferably it is about 0.05-0.2 mass part.

The mixed powder for powder metallurgy of the present invention can be formed into a green compact by compression molding according to a conventional method. For example, a compacting body can be manufactured by applying a pressure of 490 to 686 MPa (5 to 7 ton / cm ² ) after filling the mold with the mixed powder for powder metallurgy of the present invention. A sintered compact can be manufactured by sintering this compacting body according to a conventional method.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

Production Example 1
A 0.5 L four-necked flask connected to a vacuum pump was charged with 150 g of oleylamine and 136 g of palmitic acid, and heated and stirred at a temperature of 180 to 200 ° C. for 6 hours in a nitrogen stream without a catalyst. N-oleyl palmito 277 g of amide (PNT) was obtained. After adjusting the circularity of the PNT by spray drying, the obtained particles were sieved to obtain a PNT having a predetermined particle size.

Production Example 2
A 0.5 L four-necked flask connected to a vacuum pump was charged with 112.5 g of stearylamine and 144 g of erucic acid, and heated and stirred at a temperature of 180 to 200 ° C. for 6 hours in a nitrogen stream without catalyst. -259 g of stearyl erucamide (SNT) was obtained. After adjusting the circularity of the SNT by spray drying, the obtained particles were sieved to obtain SNT having a predetermined particle size.

Production Example 3
After adjusting the circularity of hydroxystearic acid amide (AA1) by spray drying, AA1 having a predetermined particle size was obtained by sieving the obtained particles.

Production Example 4
After adjusting the circularity of ricinoleic acid amide (AA2) by spray drying, AA2 having a predetermined particle diameter was obtained by sieving the obtained particles.

Production Example 5
(N-octadecenyl) gluconic acid amide (SGA), ethylenebishydroxystearic acid amide (BB1), and ethylenebiserucic acid amide (BB2) were each sieved to adjust to a predetermined particle size.

The circularity of the lubricant of the above production example was determined by measuring under the following measurement conditions using a particle shape image analyzer “PITA-1” manufactured by Seishin Enterprise Co., Ltd.
Carrier liquid: glycerin aqueous solution First carrier liquid flow rate: 8000 to 10,000 pulses
Second carrier liquid flow rate: 10000 to 12000 pulses
Observation magnification: 20 times Light control filter: ND4
Number of observation particles: 3000

The average particle diameter D ₅₀ of the lubricant was measured using a Microtrac particle size distribution analyzer (manufactured by Nikkiso Co. X-100).

Experimental Examples 1-16
PNT (melting point: 68 ° C.), SNT (melting point: 76 ° C.), AA1 (melting point: 105 ° C.), or AA2 (melting point: 45 ° C.), SGA (melting point: 150 ° C.), BB1 (melting point: 180 ° C.) ° C) or BB2 (melting point 135 ° C) in a ratio shown in Table 1 below and mixed with pure iron powder (manufactured by Kobe Steel Co., Ltd .: trade name “Atmel 300M”, particle size: 40 to 120 μm), and powder A mixed powder for metallurgy was obtained. The total amount of the lubricant was set to 0.75% by mass when the entire mixed powder for powder metallurgy was 100% by mass. Mixing was performed using a V-type mixer (manufactured by Tsutsui Rikagaku Co., Ltd.) for 30 minutes.

  The apparent density, fluidity, and critical outflow diameter of the obtained mixed powder were measured by the following methods. Moreover, the molded body density and the extraction pressure when molded using this mixed powder were measured by the following methods.

(1) Apparent density (g / cm ³ )
Measured according to JIS Z 2504 (metal powder-apparent density test method).

(2) Fluidity (s / 50g)
It conformed to JIS Z 2502 (fluidity test method for metal powder). That is, the time required for 50 g of the mixed powder to flow out of the 2.63 mmφ orifice was measured, and this time was defined as the fluidity of the mixed powder.

(3) Limit outflow diameter (mm)
A container having an inner diameter of 114 mmφ and a height of 150 mm and having a discharge hole with a variable discharge diameter at the bottom was filled with 2 kg of mixed powder with the discharge hole closed. After holding for 10 minutes, the discharge hole was gradually opened to measure the minimum diameter at which the mixed powder could be discharged, and this minimum diameter was taken as the limit outflow diameter. It means that the smaller the critical outflow diameter is, the better the flowability is.

(4) Density of compact (g / cm ³ )
A cylindrical molded body having a diameter of 25 mmφ and a length of 15 mm was produced at a pressure of 490.3 MPa (5 T / cm ² ), normal temperature (25 ° C.), and the density of the molded body was determined according to JSPM standard 1-64 (metal powder compression test method). It was measured.

(5) Extraction pressure (MPa)
(4) The extraction pressure was determined by dividing the load necessary for extracting the molded body obtained in the measurement of the molded body density from the mold by the contact area between the mold and the molded body. .

  The results are shown in Table 1.

Claims (10)

A mixed powder for powder metallurgy comprising an iron-based powder and a first lubricant A and a second lubricant B exhibiting the following characteristics.
1) First lubricant A : R ¹ —CONH—R ² (where R ¹ is a hydrocarbon group having 7 to 29 carbon atoms, and R ² is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms) )
Melting point: 50-120 ° C.
Average particle diameter D ₅₀ : 20-60 μm,
Circularity of grain projected image: 0.9 or more 2) Second lubricant B : alkylene bis fatty acid amides and R ³ —CONR ⁴ R ⁵ (where R ³ is a carbon number of 2 substituted with a plurality of hydroxy groups) 10 is an alkyl group, R ⁴ is a hydrocarbon group having 8 to 30 carbon atoms, and R ⁵ is a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms). 250 ° C,
Average particle diameter D ₅₀ : 1 to 15 μm The lubricant A is R ¹ -CONH-R ² (However, R ¹ Is a hydrocarbon group having 11 to 25 carbon atoms, and R ² Is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms). The mixed powder for powder metallurgy according to claim 1. The lubricant B is C _2-4 Alkylenebis C _14-30 Fatty acid amides and R ^Three -CONR ^Four R ^Five (However, R ^Three Is an alkyl group having 4 to 6 carbon atoms substituted with a plurality of hydroxy groups, and R ^Four Is a hydrocarbon group having 11 to 25 carbon atoms, and R ^Five Is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms). The mixed powder for powder metallurgy according to claim 1 or 2. The mixed powder for powder metallurgy according to any one of claims 1 to 3, wherein the amount of the lubricant A is 10 to 50 parts by mass with respect to 100 parts by mass in total of the lubricant A and the lubricant B. Particle size ratio of the lubricant A and lubricant B (average particle diameter D ₅₀ of the average particle diameter D ₅₀ / lubricant B of lubricant A) is, according to any one of claims 1-4 which is 2 to 30 Mixed powder for powder metallurgy. Lubricants A and lubricants melting point of the difference B (melting point of the lubricant B - the melting point of the lubricant A) is, 0.99 ° C. or less mixed powder for powder metallurgy according to any one of claims 1 to 5,.   The mixed powder for powder metallurgy according to any one of claims 1 to 6, wherein the total amount of the lubricant A and the lubricant B is 0.01 to 2 parts by mass with respect to 100 parts by mass of the iron-based powder.   The mixed powder for powder metallurgy according to any one of claims 1 to 7, further comprising a powder for alloying containing copper, nickel, chromium, molybdenum, phosphorus, sulfur or graphite.   The mixed powder for powder metallurgy according to any one of claims 1 to 8, further comprising at least one property improving agent selected from manganese sulfide, talc, and calcium fluoride. The mixed powder for powder metallurgy according to any one of claims 1 to 9 and compression molded into compacts, method for producing a sintered body you sintering the compacts.